Vand-type centrifugal machine, mainly, high-pressure compressor

ABSTRACT

A vane-type centrifugal machine is provided which is characterized in that rotor bearings and end seals are arranged directly in a set composed of the working compressor stages while, where this set mates with a cylinder encasing the set, seals are mounted for the purpose of hermetically sealing in the medium being compressed.

United States Patent [191 1111 3,733,145 Kaplansky et al. 1 May 15, 1973[54] VAND-TYPE CENTRIFUGAL [56] References Cited MACHINE, MAINLY,HIGH-PRESSURE U T STATES PATENTS COMPRESSOR I 1,362,437 12/1920 Robb..415/134 [75] Inventors: Arkady Fridmanovich Kaplansky; 1,337,87312/1931 Macmeeken lzya Yakovlevich Korenblit; Andrei 3,235,269 2/1966Olesen ..277/15 Filippovich Frenkel; Alexandr 3,384,296 5/1968 Kahane..4l5/l13 Ivanovich Zakhariev, a" of Lenim 3,532,444 10/1970 Strub..4l5/112 grad, FOREIGN PATENTS OR APPLICATIONS [73] Assignee: NevskyMashinostroitelny Zavod 411,913 4/1910 France ..415/199 R imeni V. I.Lenina, Leningrad, 174,673 10/1906 Germany 415/199 R U.S.S.R. 168,0588/1922 Great Britain ..4l5/l99 R 1 Filed: 4, 1971 PrimaryExamirier-l-1enry F. Raduazo [21] Appl No 120 956 Attorney-Waters,Roditi, Schwartz & Nissen [57] ABSTRACT [52] US. Cl ..415/l12, 415/199A, 4lz57lg/ll9s, A vane type centrifugal machine is provided which ischaracterized in that rotor bearings and end seals are 11/00 2 jfif g iarranged directly in a set composed of the working compressor stageswhile, where this set mates with a cylinder encasing the set, seals aremounted for the purpose of hermetically sealing in-the medium beingcompressed.

4 i 3 Claims, 4 Drawing Figures PATENIEDMAY 1 51975 I SHEEI 1 [1F 3PATENIE MAY 1 51975 SHEET 2 BF 3 PATENTED W1 51% 3.731145 sum 3 OF 3 F/EJ VAND-TYPE CENTRIFUGAL MACHINE, MAINLY, HIGH-PRESSURE COMPRESSOR Thepresent invention relates to turbo-machines and, more particularly, itrelates to vane-type centrifugal machines which can be used, forexample, in centrifugal compressors or in high-pressure pumps.

Presently used for obtaining high-pressure working fluid are centrifugalcompressors comprising working compressor stages combined in adetachable set, separated from each other by inter-stage seals andencased in a cylinder. In such known machines, the bearings mounting themachine rotor, as well as end seals serving to preclude the leakage ofthe working fluid from the compressor blading, are arranged outside theset.

Said known compressors suffer from a number of disadvantages. Noprovision has been made in them for direct control over gaps in theinter-stage seals. As a result, it is rather difflcult to keep the gapsminimal, which brings about inter-stage leakages of the working fluidand, consequently, a reduced efficiency of the machine. Note should bemade that this is especially true of machines featuring relatively greatpressure differences between the compressor stages.

In addition, in said known compressors, deformations of the cylinderor-of the end lids, occurring as a result of the internal pressure ofthe working fluid being compressed, are transmitted to'the rotorbearings and end seals, thus reducing the reliability of operation ofthese units.

A principal object of the present invention is to provide a vane-typecentrifugal machine featuring minimal gaps in the inter-stage seals anda high operational reliability of bearings and end seals.

This is accomplished due to the fact that the bearings mounting themachine rotor and the end seals serving topreclude the leakage of theworking fluid from the machine blading are placed inside the set,thereby insuring a direct control of the gaps in the interstage sealsand practically eliminating the effect of the cylinder deformation uponthe performance of the bearings and end seals. For the purpose ofhermetically sealing the medium being compressed, seals are provided atplaces where the set mates with the cylinder.

Said latter seals can comprise a system of annular spaces with sealingmembers, designed for the delivery and removal of the compressed andsealing media.

In addition, with a view toward compensating for the thermal expansionof the set, inside the latter on each of the elements serving to bindthe disks of the compressor stage featuring the highest pressure of theworking fluid, there may be mounted compensators of the thermalexpansion of the set.

It is preferred that, with a view to a convenient assembly of themachine, the top half of the middle portion of the set be of a smallerlength than the corresponding bottom half of the set and that, in thegaps formed between the top half of the set and the nondetachable enddisks of the set, gauge members be placed.

A vane-type centrifugal machine manufactured in accordance with thepresent invention makes for a successful solution of the problems statedhereinabove.

The present invention will be more apparent upon considering thefollowing detailed description of a preferred embodiment of theinvention, due referene being had to the accompanying drawings, inwhich:

FIG. 1 shows diagrammatically a longitudinal sectional view of thecompressor;

FIG. 2 shows a set of the working compressor stages complete with adetachable top half for control over p FIG. 3 is a connection diagram ofseals (units A) shown in FIG. 1; and

FIG. 4 shows unit B of FIG. 1, on an enlarged scale.

Referring now to FIGS. 1 and 2 of the drawings, the centrifugalcompressor described by way of example comprises a cylinder 1 whichaccommodates bottom and top halves 2 and 3, respectively, of the set ofthe working compressor stages. The set incorporates a rotor 4, statorblading elements 5 mounted between disks 6 of the set, inter-stage seals7, bearings 8 of the rotor 4, end seals 9 arranged in non-detachable enddisks 10. The set is retained in the cylinder 1 with the aid of apressure stop ill.

Placed between the top half 3 of the set and the nondetachable disks 10are gauge members 12, while in places where the set mates with thecylinder 1 there are provided seals (units A) designed for hermeticallysealing the medium being compressed.

During assembly, the rotor 4 is arranged on the bottom half 2 of the seton temporary supports with preset gaps along the inter-stage seals 7.Then are installed the non-detachable end disks 10 with the bearings 8of the rotor 4, end seals 9 and other elements of the stator part of themachine. Following a final check of the gaps along the interstage seals7, the top half 3 of the set is installed. The assembled set is mountedinthe cylinder l and fixed in place by means of the pressure stop 11.

The seal (unit A) comprises annular spaces l3, l4 and 15 (FIG. 3) andsealing members 16.

The spaces 13 communicate via channels 17 with the intake annulus of themachine (cavity of minimum gas pressure in the compressor), and viachannels 18 with a closed reservoir (not shown) for collecting the leaksof the sealing medium. Supplied to the spaces 14 via channels 19 is asealing medium under pressure slightly exceeding that in the space 13.This pressure difference is maintained automatically. Possible leaks ofthe sealing medium are drained to the spaces 15 and removed from themachine via channels 20. The sealing medium supplied to the space 14 isalso used for hermetic sealing of the end seals 9 of the rotor 4.

In order to compensate for thermal expansion of the set, on each ofelements 21 (of, unit B in FIG. 1) serving to bind the disks of thestage featuring the highest pressure of the working fluid there aremounted compensators 22 of the thermal expansion of the set (FIG. 4).

When assembling the set, a gap a, equal to the value of thermalelongation of the set, is left between the surface 23 of the bindingelement and the bearing surface 24 of the disk of the set. The pressurestop 11 provides a preliminary force sufficient for a reliable retentionof the set in the cylinder 1. With a pressure increase in the machine,the gap a is eliminated, and between surfaces 25 and 26 there forms agap (shown with broken line in FIG. 4) sufficient to compensate for thethermal expansion of the set. Therefore, the thermal elongation of theset is not transmitted to the pressure stop 11.

What is claimed is:

l. A vane-type centrifugal machine adapted for constituting ahigh-pressure compressor, said machine comprising: a cylinder, a rotor,inter-stage seals, working compressor stages including blading andcombined in a detachable set mating with said cylinder, said stagesbeing separated from each other by said interstage seals and encased insaid cylinder; bearings mounting said rotor within said cylider andextending through said stages; end seals on said cylinder to pre cludethe leakage of working fluid from said blading; said bearings and saidend seals being arranged directly in the set; and further seals tohermetically seal the medium being compressed, said further seals beingmounted where said set mates with said cylinder, each said further sealcomprising a system of sealing members with annular spaces beingprovided therebetween and adapted for the supply and removal ofcompressed and sealing media, said annular spaces including a firstannular space communicated with the compressor cavity of minimum gaspressure, a second annular space for the supply of a sealing medium anda third annular space for the drainage of the sealing medium, the secondspace being located between the first and third spaces and the mediumsin the second space being at higher pressure than that in the firstspace.

2. A vane-type centrifugal machine as claimed in claim 1 comprisingmeans for compensating thermal expansion inside the set.

3. A vane-type centrifugal machine as claimed in claim 1, wherein saidset includes top and bottom halves and the top half of the middleportion of the set is of a smaller length than the corresponding bottomhalf of the set whereby there are formed gaps, compris ing gauge membersin the gaps.

1. A vane-type centrifugal machine adapted for constituting ahigh-pressure compressor, said machine comprising: a cylinder, a rotor,inter-stage Seals, working compressor stages including blading andcombined in a detachable set mating with said cylinder, said stagesbeing separated from each other by said inter-stage seals and encased insaid cylinder; bearings mounting said rotor within said cylider andextending through said stages; end seals on said cylinder to precludethe leakage of working fluid from said blading; said bearings and saidend seals being arranged directly in the set; and further seals tohermetically seal the medium being compressed, said further seals beingmounted where said set mates with said cylinder, each said further sealcomprising a system of sealing members with annular spaces beingprovided therebetween and adapted for the supply and removal ofcompressed and sealing media, said annular spaces including a firstannular space communicated with the compressor cavity of minimum gaspressure, a second annular space for the supply of a sealing medium anda third annular space for the drainage of the sealing medium, the secondspace being located between the first and third spaces and the mediumsin the second space being at higher pressure than that in the firstspace.
 2. A vane-type centrifugal machine as claimed in claim 1comprising means for compensating thermal expansion inside the set.
 3. Avane-type centrifugal machine as claimed in claim 1, wherein said setincludes top and bottom halves and the top half of the middle portion ofthe set is of a smaller length than the corresponding bottom half of theset whereby there are formed gaps, comprising gauge members in the gaps.